Examples of prior art types of band clamps include U.S. Pat. No. 4,742,600. A slot in one end portion has on its edges clearances or recesses in order to allow a T-shaped projection from the other end portion to pass through. The T-shaped projection allows the end portions to be pre-fastened, before the closure elements are engaged by the locking mechanism during tensioning of the clamp.
Notwithstanding the foregoing types of band clamps, there are still major problems involved. The projection is typically formed at the end of the radial inner end portion and bent radially to the outside. When inserting the projection into the slot there is always the danger that it may be bent into its original shape or even get bent further and prevent insertion by not having enough clearance in the longitudinal edges of the slot. Furthermore, the radially outer end portion could rotate at right angles to the circumferential direction of the band around the projection due to accidentally applied lateral forces. This will prevent the end portions of the band from assuming the required relative position to each other when applying tension to the band.
It is, therefore, an object of the present invention to produce a clamp that avoids the danger of bending the projection at the time of insertion into the slot and insures retention of the relative position of the end portions while tension is being applied to the band.